Files
microdot/examples/login/pbkdf2.py
Miguel Grinberg d807011ad0 user logins
2025-02-04 00:04:55 +00:00

48 lines
1.5 KiB
Python

import os
import hashlib
# PBKDF2 secure password hashing algorithm obtained from:
# https://codeandlife.com/2023/01/06/how-to-calculate-pbkdf2-hmac-sha256-with-
# python,-example-code/
def sha256(b):
return hashlib.sha256(b).digest()
def ljust(b, n, f):
return b + f * (n - len(b))
def gethmac(key, content):
okeypad = bytes(v ^ 0x5c for v in ljust(key, 64, b'\0'))
ikeypad = bytes(v ^ 0x36 for v in ljust(key, 64, b'\0'))
return sha256(okeypad + sha256(ikeypad + content))
def pbkdf2(pwd, salt, iterations=1000):
U = salt + b'\x00\x00\x00\x01'
T = bytes(64)
for _ in range(iterations):
U = gethmac(pwd, U)
T = bytes(a ^ b for a, b in zip(U, T))
return T
# The number of iterations may need to be adjusted depending on the hardware.
# Lower numbers make the password hashing algorithm faster but less secure, so
# the largest number that can be tolerated should be used.
def generate_password_hash(password, salt=None, iterations=100000):
salt = salt or os.urandom(16)
dk = pbkdf2(password.encode(), salt, iterations)
return f'pbkdf2-hmac-sha256:{salt.hex()}:{iterations}:{dk.hex()}'
def check_password_hash(password_hash, password):
algorithm, salt, iterations, dk = password_hash.split(':')
iterations = int(iterations)
if algorithm != 'pbkdf2-hmac-sha256':
return False
return pbkdf2(password.encode(), salt=bytes.fromhex(salt),
iterations=iterations) == bytes.fromhex(dk)